Telegraph system



March 4, 1947.

TELEGRAPH SYSTEM E. F. WATSON Filed Deo. 6, 194s QN MN IN1/@N TOR 5F. WA rso/v Wa/M... JMW.

A 7' TOR/VE V fatedjo its lower positionwhere TA and TB are controlled mechanically from the shaft driving brush arm 32 and cause the re spective transmitters to advance their respective perforated tapes and to sense the code combinations punched in them. Each of these transmitters is supplied with a controlling tape which in the exemplary embodiment of the invention set forth herein is a perforated or punched tape. These controlling tapes may be prepared by wellknown keyboard apparatuslocated at the same station as the transmitters or these tapes may be prepared by a reperforator in response to received signals, Furthermoreyinfthe lattercase the signalsfor the different channels may .but need'notoriginate at the same station and need not originate at the station where the transmitters TA and TB are located. When reperforators are employed to prepare the controlling tapes' they will usually be located adjacent the trans-` mitters and record signals received overa line from a more remote point in either or both of.

the controlling tapes. In addition, the supply of. perforated tape is employed to control the op"' eration of the respective transmitters in the same manner as set forth in my said patent. afAsshown in the drawing, switch- I2 is Yoperthe system will operateas .a single-channel system as will be described hereinafter. When switch I2 is manually .operated to .itsupper position, the system will doperate asa two-channelsystem in the same manner/as described in my said patent. The transfmission `path 20 leading from the distributor 3I .extendsto a. radio transmitter I3 of any one of .the usual Well-known typesof radiotransmitters suitable -forthe transmission of telegraph. sig,-

naling impulses.- The following United States patents disclose typical telegraph transmitting .and .receiving arrangements suitable for cooperatingin applicants improved transmission sys- .win32-,012,407 granted to Schmitt on August- 27, 1935;,,Figs. 15 and 16 v $2,046,328 granted to Kleinschmidt'et al..onv July-.7, 1936; Re. 16,485 .granted tog-,BradyfNovember 23, 1926; 1,523,377 granted-to Brady January 13, 1925; and 1,582,331 granted toBrady onv April 27, 1926. -5, y lilach ofthe vabove-identified patentsl is: hereby made'a part ofthe present application as-if fully rincluded herein. The presentinvention is not in 'janywwaylimited tothe 4systems shown in the .abovej-fidentied patents and maycooperatewith many other radioorwire communication trans- Agmission systems. Y f v Y Y I5 represents'the radio receiving device vwhich -cooperate's with the transmitting device I4. Ra- ;.zdio 'receiver 15 may be of any type suitable for receiving radio telegraph signals and' may be similar. to the radio receiving arrangements set forth in the'above-identifled patents. Theout- .put ofthe radio receiver' I5 extends to -two or lmore receiving; devices I6 and II connected in rs'eries. Asset :forth in my above-identified pat,- -ent, these receiving devicesicomprise two differentstart-stop printers.4 The receiving ydevices I6 Y jand'- I1 insthepresent application may also comfprise .two different telegraph-` printers, reperfora- Y' tors. or they may I.include regenerative repeaters aswell as' printers and other suitable equipment.

'As''speciiically.disclosed in vthe drawing, the re- 1 .'ceivers I6.-and I'I are represented as regenerative repeaters 1 froml which lines' ,22-, and l 23 respeci tively; extendto.receivingprinters :Io-fand I9. Morexspecically for exampledistributor 3l may 'be connected to the ,radio-transmitter shown in mitting distributor I0 shown therein. Also the control magnets of the two receiving devices IE and I1 may be connected in series with the armature 50 of the relay 39 of Fig. 2 of the Schmitt patent in place of the printer magnet 55 shown therein.

Exemplary regenerative repeaters and other receivers suitable for connection in series withthe output of the radio receiver I5 and also at the end of the transmission paths 22 and 23 are described in detail in United States Patents 2,104,251 granted to Zenner on January 4, 1938; 2,104,273 granted'to Potts January 4, 1938; 2,105,173 grantled to Zenner etal. on January 11,1938;f1,745,633

874 granted to Reiber on September 29, 1942;

2,273,909'grantedto Swan on February 24, 1942; and 2,318,026 granted to Swan May 4, 1943.

The vforegoing patents are hereby made a part ofv the present application as if fully included herein.

The transmission channels 22 and 23 have each been represented in the drawing by two conductors. VIt will be appreciated by. persons skilled in the art that any suitable type of transmission channel may extend from the regenerative repeaters I6 and I'I to the respective receiving devices I8 and I9. For example, these transmission channels may be open-wire lines, cable conductors, telegraph channels of composite telephone and telegraph lines, channels of voice frequency or high frequency carrier current systems, radioY transmission channels, channels of time kdivision multiplex systems and other well-known types .of telegraph transmission channels. In addition, the

,transmission paths may include any combination of the foregoing types-of transmission channels and the associated terminal and repeater equipment for the transmission of signals thereover.

.In addition any suitable type of .transmission may be employed over the respective channel. Inasmuch as the operation of such types of transmisvsion channels and combinations thereof are well lunderstood by persons skilled in the artandsince ,they'operate in their Vusual manner in cooperation with applcants present'inventionrdetailed de:-

scription thereof need not be repeated herein.M

The transmission channels extend from the r'e- -peaters IB and Il to the reeciving devices I8 and" i9V which may be locatedV at the same or diierent places.` It will alsoA be obviousftoY personsskilled Y in thev art that one of the receiving devices l5 or IIfmay. be -a printer and the other a regenerajtive repeater. It is alsroevident that. vmore than two receiving devices may be connectedtY the output of the radio receiver inr which case certain of the receiving ,devices will respond -thesignals from one of-the channels and other of the ceiving devices will respond signals-from another channel. l ,y As. `setV forth n. my above-identiied, patent, the orientation of -the receiving .devicesvlii and I'I whether theybe printera'fregenerativerepeat:- ers or other monitoring devicesare adjusted as set forth in Amy above'fidentiiied patent. f

lFig. 2 has been includedin the, drawing. to show more clearly the manner of operationfoi the sys,-v tem. The first horizontal line.v of Fig, Z'shlys the Contacts' lo 'of the transmitterrA wenn are Y Y closed for-,the -transmissionot theletter X signel .by Vtlef transmitter' *.TAzf over the; A- channel Qf-the system;f V'Ihesecond e shows the par- 'fFiei 1--s-.ofthe Schmitt 'patentin Place of the trans..- 79 Meulan .contacts l lf off.the-transmittrllli3'einigt 4revolution during ywhich, the letter X signal is :transmittedover the A Achannel and the letter Y signal is transmitted over the Bchannel. The

,fourth line fromthe top ofFig. 2 shows the orientationsetting of the receiving camsinthe re- :ceivingy devices I6 designated RRA inl Fig. 2.`

The-,next line showsthe orientation setting of thereceiving cams of the receiving devicegl'l designated RRBin Fig-:2. Thenext two lines show that, the ,selection received by vthe respective `re 1'ceiyi'ng devices; correspondsy to the characters v:transmitted by the respective transmitters. For

the operation of the system, as described. .above and as setforth, in my above-identiedpatent, as -a two-channel system it has :been assumed .that .the manual key I2 has been operated tothe two- V`chan-nel position. The key I2 is a lockingkey and wiilremain either in the two-channel position or 4the*single-channel position. WhenA the key is in :the two-channel positionythe transmitters are connectedto the respective segments ofV the distributor 3l lin the same manner as set forth in my above-.identified patent.

As will be apparent to those skilled in theart, the possible variation of the orientation setting of the receiving cams of the receiving devices dur.

ying operation in the two-channel system is only half of that possible in a single-channel system.

In, other words, the orientation setting of the receivingk cams of the device RRB extends only between/three vertical lines of Fig. 2. That is, ltxextends only from the position shown as far Aas the next line on `either side thereof. In the -usual single-channel start-stop system the possible orientation adjustments for an ideal transmission system would extend for two vertical lines on each side of the usual orientation position .selected for the receiving printer. It is thus apparent that `the operating margins of the receiv- .ing devices and of the transmission channel is yless 'for the two-channel system than for a singlel channel system.

The smaller operating margins are acceptable at'times when traffic is Aparticularly heavy and/or thetransmission channel is better than usually provided for in single-channel systems.

However, radio channels attimes vary so that it may be possible to operate a two-channel sysv-te'm thereover and at other times the margins-of the;transmissionr channel will be insuiicient to Ipermit .the operation of a two-channelsystem. .IAlso traic over such a-system varies widely-from .time to time so that during periods of heavy traf- -fic it may be' necessary to accept thernargins 44ofwa two-channel system in order to be ablevto transmit the tralic load. If, during the times of light traflic or-poor transmission or single-channel*operation the tape is only inserted in 4one of the transmitters and the system 'operated as one channel of a two-channel system, the margins of the operating channel lwill 'not' in any way have been improved and at Athe-'same time the` other channel ofthe system is idle. f In accordance with the present invention switch l2; is provided'for 'totally 'disabling the second 4'channel and rearranging the connections so that thesingle remaining channel vwill occupy substantially the entire channel time and Willhave substantially the same margins oi?r operation as the usual -s'ingleechannel start-stop 'telegraph system. Upon.- thef opera-tion? ci` key f I2@ te the one-channel position, the A andthe B11 segments Vofthedistributor are.,connected rtogether and connectedto the` transmitting,A contacts I Iy of the ter 'IBcontro1s1the potential-'supplied to vthe'A I and l?-,.se, rmentsA of; the transmitter .which` are connected together and thus are essentially equivalent-to theusual distributor of a single-channel start-stop system. Theo-perationof they switch l2l to its lower position as. shown in the draw.- ing/ in addition to'. connecting the A, and the B segmentsV together and to Athe* transmitting. contacts li ottlieftransmitterTB alsotransfers the X segment I4 from connection with-thelstoprsegine'nt 25andY connects. it to the start "segment-26 ofthe distributor` 3|. In the exemplary embodiment of theinvention describedin detail herein, the X lsegment is. one-quarter the length' of the usual start-stop distributor selection segments and one-half thelength of thesegments IAy and IB, 2A, 2B', etc.

Thus, with theswitch I 2 set in the one-channel position a slightly longer start pulseI is transmitted preceding each of the code combinations. Thelast line in Fig. 2 shows the. corresponding signal as transmitted by the transmitting distributor 3|. It will be noted that thestart pulse is now slightly longervthan the start pulse shown in the third line which is transmitted during the two-channel operation of the system. H

Inasmuch as the rotation of the receiving` cams e is initiated in the beginning of the start-pulse, the orientation setting of the receiving cams shown inthe fourth and fifth lines of Fig. 2 with respectto the received signals remains unaltered. However, the selecting or significant pulses of the signals as transmitted during single-channel operation have been advanced a quarter of va pulselength. to the right as shown in Fig'. v2. Consequently, the orientation setting of the receiving cams of the receiver'RRB is in the middle of the respective impulses ofthe receivedsignals. Thus the receivingrcams of the printer RRB are properly oriented withrespect to the received sig.. nals and have-substantially the fullmargin 'ofA the usual .single-channel in astart-stop telegraph system.` In other'words, the orientation setting vOfth'ereceiving cams are such that the'selection is made substantially in the middle of the received pulses. Furthermore this selection'interval may be moved through substantially the samerdistance as in the standard start-stop sysltem without causing errors. l Y 7 f Another way of considering the operationo f Vthe transmission system is that' duringthe tw'ojchannel operation theA margin ofjoperation-or orientation setting `of the receivedsilgnals visv subjstantially half of the margin usually available in single-channel start-stop systems. If onlyone Voi'- the two channels operating andthe other channel is idle the` operating margins of the remaining channel are substantiallythe same as before and at thesame'time one-half'of-the available transmitting channel-or line is idlei- If the connections tothe transmitting distributorarey changed so that theoperating channel employs the entire line time then therarige of orientation setting is substantially the same asferfa-single-r Ymultiplex distributor, connections stead it is made near the end of eachmof the sig'- nal pulses. In order toeliminate the necessity for realigning or readjusting the orientation setting of the receiving selector mechanisms of all or at least one of the channels every time the system vis switched from a 'single channel to a multichanfnel, or vice versa, the length of the start pulse is altered as described above by sending a longer start pulse preceding each of the code combinations when the system is operated as a, singlechannel system. The orientation setting of the `receiver cams in one of the receiving devices, viz., RRB, with respect to the received signals will Vthen be correct to select substantially the mid- -dle interval of the received signals both during single-channel operation and multichannel operation. It will be quite apparent to persons skilled in the art that it is much' easier to shift the connection of the short X segment of the Atransmitting distributor 3l each time a change ,is made from the one-channel to the two-channel operation, or vice versa, than itis to realignV and .reorient either or both of the receiving devices Vat the receiving end so that they will properly receive the transmitted signals with the least possible number of errors even during adverse trans- Y mission conditions.

In the exemplary embodiment of the invention Adescribed herein the B channel has been selected as the channel to be operated during singlechannel operation. During single-channel operation the receiving equipment of the A channel will in all probability print unintelligible letters and characters because the orientation of there- `ceivlng 'cams of this machine are set at the tran'- or the beginning of theV next succeedingpulse. f The operator or attendant at the receiving vsta- Y tion upon noting the unintelligible characters being printed by the receiving device I6 or repeated thereby to the receiving device I8 may cause Vthe operation of these devices to be suse pended either by short-circuiting the repeating relays orcontrol magnets thereof or by removing the source of power therefrom. Then when the system is transferred back to a two-channel system it willbe necessary to so inform the operator or attendant at the receiving station and instruct him to condition the other channel for reception of the signals. 1

As will be readily apparent to persons skilled in the artif it is desired to employ the A channel for single-channel operation, instead of the B channel as described above, the start pulse would beshortened instead of being lengthened. If the start pulse is shortened one quarter pulse length then the received signals will be received relative to the orientations of the receiving devices such that RRA will select the center portion of each of the pulses of each code group of pulses. e

Thus, by varying the length ofthe start pulse it is possible, in effect, to change the orientation `of the receiving cams of the receiving devices.

What isclaimed is:

1. In a multichannel lstart-stop multiplex system,v a telegraph transmitting station, a, .start-stop Y extending therefrom! to a plurality of transmitters, apparatus for sending a single synchronizing pulsefcr each revolution 'offsaid distributor, switching ap'- (paratus 'for transferring the connections from said `distributor to said multiplicity of transmitters to a single one of said transmitters, apparatus operative incident to the operation of said switching apparatus for varying the length oisaid synchronizing pulse.

2. In a multiplex a telegraph transmitting station, a start-stop multiplex distributor, connections extending therefrom to a plurality of transmitters, apparatus for sending Aa synchronizing pulse for each revolution of said distributor, Yand switching y equipment for varying the length of said synchronizing pulse in accordance Vwith the number of channels operative during the succeeding revolu- Ytionof said distributor.

3. In a multichannel start-stop multiplex system, a telegraph transmitting station, a start-stop multiplex f distributor, connections extending therefrom toa plurality of transmitters, apparatus for sending a start pulse at the beginning of each revolution of said distributor, switching apparatus for transferring the connections from said distributor to said multiplicity of transmitters to a single one of said transmittera'apparatus operative incident to the operation of said switching apparatus for increasing the length of said start pulse. f

4. Ina multiplex start-stop telegraph system, a telegraph transmitting station, a start-stop multiplex distributor, connections extending therefrom to a plurality of transmitters, apparatus for sending a start pulse for each revolution of said distributor and switching equipment for transmitting a start pulse of varying length, and apparatus operative incident to the operation of the particular channels operative during the succeeding revolution of said distributor to determine the length of start pulse transmitted during that revolution.

5. In a multiplex start-stop system, a telegraph transmitting station, a start-stop multiplex transmitting distributor thereat, connections extending from said distributor toa plurality of transmitters, apparatus for sending a single start pulse for each ;revolution of said distributor, a receiving station,

a transmission channel extending from said distributor to said receiving station, a receiving device individualto each of said transmitters connected to said channel at said receiving station,

one of said receiving devices including regener` ative repeating apparatus, equipment for supplying start pulses individual to permutationV code signal combinationsVregeneratedin said repeating apparatus, apparatus for causing each of said Vvreceiving devices to respond to each of said start signals at a first time, apparatusfor causing one of said receiving devices only to respond to each of said start signals at a second time and` means including aswitch; connected to said distributor -for transmitting over said channel permutation 4code signal combinations having signal elementsV -of half normal duration at said first time and of full normal duration at said second time.

6. In amultiplex start-stop telegraph system,

.a telegraph transmitting station, a start-stop multiplex transmitting distributor thereat, apparatus for transmiting a singlestart pulse for each revolution of said distributor, a plurality of telegraph-transmitters, apparatus for connecting said transmitters to said distributor, apparatus operativeincident to a Vchange in vthe number of said transmitters connected to said distributor to vary ythe'length of the start pulse transmitted by said start-stop telegraph system,

distributor, arec'eiving. station, af p1ura1ity of regenerative repeaters. at Sadregeiving Stative C011- nectd 'to said channel 'including apparatus responsive to said start signal/equipment at said receiving station" for separatingthie 'signals transmitted during one revolutipnyof said distributor into'a ,lurality of independent trains of signals, means "for".regenerating "andftransmitting Lsaid trains "o signals; and vapparatus ,for translating said single startfpulse" into La start pulse before each of said trainsso regeneratedand repeated.

7.,Asignaling systemeomprising a transmit.- ting rininalprovided with start-stop distributor ir'ans" fftr'ansmitting tw V"code combinations each belonging to a diierent sub-channel per start-stop cycle, switching means for lengthening the duration of the individual signal elements of a combination and lengthening the duration of the start pulse of said distributor means to transmit one c ode combination belonging to one of said sub-channels upon each start-stop cycle of said distributor means in combination with receiving means comprising two regenerative repeaters correctly orientated for regenerating and retransmitting signals ,from the respective sub-channels when said distributor means is transmitting two code combinations per start-stop cycle and one iof which without switching is correctly orientated for regenerating and retransmitting signals from said one sub-'channel when said transmitter means is rearranged to transmit one code combination, and separate outgoing channels for said regenerative repeaters. l

8. In a start-stop telegraph communication system, a telegraph transmission path, a plurality of receiving devices eachl including means for selecting a different portion of each of the code pulses received thereby for the control thereof, transmitting apparatus for transmitting code groups of pulses to said receiving devices', and equipment for operating said transmitting apparatus to control selectively which portion of the transmitted pulses are selected by said receiving devices by transmitting different length of start pulses before said Vcode groups of pulses.

9. In a start-stop telegraphl system, a telegraph line, a receiving device connected thereto including means for selecting a portion ofeach of the code pulses received thereby'for the control thereof, a second receiving device also connected to said line'and including means for selecting a po'rtion of each of the code pulses received thereby ,Y

for the control thereof whichportion is dinerent from the portion of each of the codepulses selected by said first receiving device, transmitting apparatus also connected to said telegraphline and apparatus for controlling the lengthof theV start pulse transmitted .by said transmitting apparatus preceding each group of codepulses.

10. In a telegraph system, a telegraph line, a first start-stop receiving device connected to said line including apparatus for selecting a portion e of each of the code pulses received thereby for the control thereof, a `second receiving device also connected to said telegraph' line and including means for selecting a portion of each of the code params.,

no f vices I'coniprising apparatus., gior.. controlling.: th. length-.of the start vpulse..preceding ,saidvgroupstof codegpulsestransmitted by said transmitting- .ap-

- y1,1..}In a startestopjtelegrapl'isystem anales graph transmission line, a `,receiving device-aceite` nectedthereto for; receiving start pulses followed by code. pulses, a second receiving device alsoconnected to said line eachfofsaid receiving. devices including apparatus set into operation by start pulsesreach oijsaid receiving devices also including selective apparatus operative at predetermined intervals of time after the reception of said start pulses, apparatus for adjusting said predetermined intervals of time differently for said re'- ceiving devices, transmitting'apparatus for transmitting code pulses preceded by start pulses and apparatus for selectively directing said code pulses to said receiving devices comprising apparatus for varying the length of the start pulse preceding each of said groups of code pulses.

12. In start-stop transmitting apparatus, a distributor having a stop segment, a start segment, a special segment, and a plurality of code segments, said special segment normally being connected to said stop segment, a pair of tape transmitters each connected to half of said code segments of said distributor in alternate sequential order, means to alter the connections between said tape transmitters and said distributor whereby one of said tape transmitters will be disconnected from said distributor and the other of said tape transmitters will be connected to all of said code segments, and means operating conjointly to cause said special segment to be disconnected from said stop segment and connected to said start segment. 13. In a telegraph transmission station, a pair of tape transmitters, each of said transmitters including signal forming means for forming permutation code signals, means for simultaneously operating said signal forming means, a distributor for transmitting the permutation code signals, saidl distributor having a pluralityl of code segments, a plurality of circuits connecting said first transmitter to alternate code segments of said distributor, a plurality of circuits connecting said second tape transmitter to alternate code segments on said distributor, successive code seg'- ments onv said distributor vassociated with said said electrical circuits whereby one-'0f said tape transmitters is disconnected from its associated code segments of said distributor and the other f of said tape transmitters is connected to allv or pulses received thereby for the control thereof,

which portion is different from the yportion of the code pulses selected by said rst receiving device; start-stop telegraph transmitting apparatus also connected to said channel for transmitting vto yboth of said receiving devices groups of code pulses preceded by start pulsesyapparatus for selectively directing messages' to said receiving desaid code segments of said distributor.

14. Telegraph transmitting apparatus comprising a pair of tape transmitters, a distributor having a plurality of code segments thereon'halrof which are connected to eachlof said tapel'transmittersvin alternate sequential order, and means `to alter the connections between said distributor and said tape transmitters whereby one )only of said tape transmitters is connected to all ofr said code segments of said distributor, the other of said tape transmitters being simultaneously entirely disconnected from said code segments of'l said distributor. l.

15. In start-stop transmitting apparatus, a distributor having a, plurality of code segments, a pair of tape transmitters each connected to half of said code segments of said distributor in alternate sequential order, and means to alter said '11 connections whereby one V`of ysaid tape trans-"- mitters'is disconnected fromvsaid code segments *ofsaid distributor andthe code segments disconnested therefrom are connected to adjacent code segments connected to the other ofxsaid tape L transmitters' whereby the vother of said tap'e transmitters is connected to al1 of said code segmentsof said distributor, eachconnection? being toftwo'of said code segments. s f

Y EDWARD F. WATSON.

E i" a .REFERENCES 'armany Nurrnber 'Y v2,104,251

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